Three generations of family members live in the house on Concord Street in St. Paul, and the grandmother made it clear to all: No guns allowed, said her daughter, Michelle Olson.

But a combination of forces -- a threatened drive-by shooting, fear, and a man's access to an AK-47 assault rifle -- is alleged to have led to the shooting death Sunday of Jacob MacKenzie, 15.

Alfredo Gutierrez-Gonzales, 19, who was dating Olson's niece, brought the gun to the house, authorities say, and after struggling to load it, shot MacKenzie in the head, according to a second-degree murder charge filed against him Friday.

In an interview with police, Gutierrez-Gonzales said that the shooting was an accident, and that he hoped to apologize to MacKenzie's mother.

But Olson, who buried her son Friday, is not about to accept, saying: "He took the only thing away from me that I truly, deeply love."

On Monday, Jayna Emerson, who is Olson's niece, made a public plea for boyfriend Gutierrez-Gonzales to turn himself in. He did so Thursday morning, and charges were filed against him Friday in Ramsey County District Court. He also is accused of second-degree manslaughter and illegal possession of a firearm.

Bail was set at $250,000.

The complaint gives this version of events:

Gutierrez-Gonzales was on the family's front porch, where he often slept when visiting, struggling to put a magazine into the semi-authomatic AK-47, a weapon that is legal to own. He had brought it to the house, he told police, after he received text messages from friends living there who said they feared the house was being targeted for a drive-by shooting.

A male resident, identified as "J.A.E.," told police that he was on the porch, too, when Gutierrez-Gonzales gave him the weapon to see if he might have better luck inserting the magazine. The effort failed, J.A.E. said, "because the frame of the gun was messed up or bent."

Gutierrez-Gonzales tried again to load the gun, at which time MacKenzie approached, J.A.E., the witness, said, and the weapon suddenly went off.

A bullet struck MacKenzie in the head. He was pronounced dead at the scene after police arrived about 12:25 a.m.

J.A.E. said that after running into the house to tell others to call 911, he returned to the porch to find that Gutierrez-Gonzales was gone.

A police officer and his K-9 partner later found the AK-47 in a ditch about six blocks away.

Gang involvement

In a police interview, Emerson said that boyfriend Gutierrez-Gonzales was a member of the Brown Pride street gang, and that she had sent him a text message earlier that evening saying she was scared "because another man had threatened to shoot at the house."

After his surrender, Gutierrez-Gonzales told police he had received multiple text messages from friends at the house, that he found a gun and was trying to put in the magazine when MacKenzie walked in. He made a move to hide the rifle, he told police, but MacKenzie told him "it was OK," and when he picked the gun back up, it abruptly fired.

Gutierrez-Gonzales refused to say where he got the AK-47.

Earlier this year, records show, he pleaded guilty in Hennepin County District Court to terroristic threats after sending a MySpace message to a Bloomington man warning him that he owned an AK-47 and an Ingram Mac 11 machine pistol, and was a Brown Pride gang member.

As part of the sentence for that offense, he was prohibited from possessing a firearm.

Police spokesman Peter Panos, asked about fears that the house might be shot at, said Friday: "Our detectives don't have any indication of why that would be -- why that house would be targeted."

At the house, where both the victim's mother and the suspect's girlfriend live, the last week has been difficult, said Olson, as she prepared for Friday morning's funeral.

She loves her niece, she said, and has tried to put herself in her place. But, Olson said, "if I was dating somebody, and [he] killed one of my family members, even out of stupidity, I don't know how I could love that person."